Redwood City, California climate: Normal weather by month, frost dates and records
Redwood City's normal year runs from 40°F December nights to 81°F July afternoons, with 19.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.2°C, December lows of 5°C, July highs of 27°C, 483 mm of precipitation a year.
- NOAA stationRedwood City
- Station IDUSC00047339
- Location37.48°N 122.24°W
- Elevation31 ft (9 m)
- From the center3 miles
- Population82,982
On October 23, the normal high in Redwood City is 73°F and the normal low 48°F, and the chance of measurable rain or snow is 10%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Redwood City.
- Jan 59° 41°
- Feb 62° 43°
- Mar 65° 45°
- Apr 69° 47°
- May 73° 50°
- Jun 79° 54°
- Jul 81° 57°
- Aug 81° 57°
- Sep 79° 54°
- Oct 75° 50°
- Nov 65° 44°
- Dec 59° 40°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Redwood City each month?
July is the warmest month, with normal highs of 81°F; December the coldest, with normal lows of 40°F. The most precipitation falls in December (3.92 in), the least in July (0.00 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 59°F | 41°F | 49.7°F | 3.81 | 9 | <1 | 3 | 9 h 50 min |
| February | 62°F | 43°F | 52.2°F | 3.65 | 9 | <1 | 1 | 10 h 50 min |
| March | 65°F | 45°F | 54.9°F | 3.02 | 9 | <1 | <1 | 11 h 50 min |
| April | 69°F | 47°F | 57.5°F | 1.15 | 5 | <1 | <1 | 13 h 10 min |
| May | 73°F | 50°F | 61.6°F | 0.46 | 3 | 1 | <1 | 14 h 10 min |
| June | 79°F | 54°F | 66.2°F | 0.16 | 1 | 4 | <1 | 14 h 40 min |
| July | 81°F | 57°F | 68.8°F | 0.00 | <1 | 4 | <1 | 14 h 30 min |
| August | 81°F | 57°F | 68.7°F | 0.04 | <1 | 4 | <1 | 13 h 40 min |
| September | 79°F | 54°F | 66.8°F | 0.07 | 1 | 4 | <1 | 12 h 30 min |
| October | 75°F | 50°F | 62.2°F | 0.87 | 3 | 2 | <1 | 11 h 20 min |
| November | 65°F | 44°F | 54.3°F | 1.87 | 6 | <1 | <1 | 10 h 10 min |
| December | 59°F | 40°F | 49.4°F | 3.92 | 9 | <1 | 3 | 9 h 40 min |
| Year (annual) | 70°F | 48°F | 59.4°F | 19.02 | 55 | 18 | 6 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 15°C | 5°C | 9.8°C | 97 mm |
| February | 17°C | 6°C | 11.2°C | 93 mm |
| March | 19°C | 7°C | 12.7°C | 77 mm |
| April | 20°C | 8°C | 14.2°C | 29 mm |
| May | 23°C | 10°C | 16.4°C | 12 mm |
| June | 26°C | 12°C | 19.0°C | 4 mm |
| July | 27°C | 14°C | 20.4°C | 0 mm |
| August | 27°C | 14°C | 20.4°C | 1 mm |
| September | 26°C | 12°C | 19.3°C | 2 mm |
| October | 24°C | 10°C | 16.8°C | 22 mm |
| November | 18°C | 7°C | 12.4°C | 47 mm |
| December | 15°C | 5°C | 9.7°C | 100 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047339; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Redwood City?
Normal highs sit between 65°F and 85°F in March, April, May, June, July, August, September and October. Of those, July has the fewest days with rain (0).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047339.
When is the last frost in Redwood City?
In Redwood City, the last spring frost (32°F) comes after January 17 in half of years and after February 16 in one year in ten; the first autumn frost comes before December 12 in half of years and before November 24 in one year in ten. A night at 32°F or colder comes at all in 88% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 171 year in 10 after February 16; 9 in 10 after December 20
- First autumn frost, half of years before
- December 121 year in 10 before November 24; 9 in 10 before January 14
NOAA puts the median frost-free season at 333 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after December 31 in half of springs and before December 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Redwood City in zone 10a across its 3 ZIP code areas (10a in 94063, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Redwood City's NOAA station is in zone 9b: the coldest night of a typical year reaches 29°F (22 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00047339; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Redwood City ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Redwood City's 3 ZIP code areas are all in zone 10a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Redwood City?
In a normal year in Redwood City, 18 days a year reach 90°F (2 of them 100°F or more), 6 nights fall to 32°F or colder and 55 days bring measurable precipitation.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 6a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 55a normal year
The highest temperature in this station's record (since 1930) is 110°F, on July 15, 1972; the lowest is 16°F, on January 11, 1949.
The wettest calendar year on that record is 1998, with 31.52 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00047339; records: ACIS (NOAA Regional Climate Centers), station USC00047339. Records use complete months only; a month missing more than three days is left out.
How sunny is Redwood City?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Redwood City, 4.7 kWh per square metre a day. June is the sunniest month (84%) and December the cloudiest (74%). Among the 459 U.S. places of 50,000 or more, that ranks tied 125th (with 50 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 76% | 2.5 |
| February | 77% | 3.4 |
| March | 79% | 4.6 |
| April | 82% | 6.0 |
| May | 81% | 6.7 |
| June | 84% | 7.3 |
| July | 78% | 6.5 |
| August | 77% | 5.8 |
| September | 82% | 5.1 |
| October | 83% | 4.0 |
| November | 81% | 2.8 |
| December | 74% | 2.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Redwood City need?
A normal year in Redwood City brings 2,519 heating degree days, 53% fewer than the median U.S. place (5,373), and 475 cooling degree days, 48% fewer than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,606 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 474 | 0 |
| February | 358 | 0 |
| March | 312 | 1 |
| April | 231 | 6 |
| May | 132 | 28 |
| June | 45 | 81 |
| July | 8 | 126 |
| August | 8 | 121 |
| September | 29 | 83 |
| October | 116 | 29 |
| November | 322 | 1 |
| December | 484 | 0 |
| Year (annual) | 2,519 | 475 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047339. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Redwood City been warmer than normal lately?
2025 averaged 60.3°F, 0.9°F above the 1991-2020 normal of 59.4°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 59.3°F | −0.1°F | – |
| 2022 | 59.6°F | +0.2°F | 14.87 |
| 2023 | 59.1°F | −0.3°F | 26.69 |
| 2024 | 60.8°F | +1.4°F | 20.18 |
| 2025 | 60.3°F | +0.9°F | 15.87 |
Over 75 complete years from 1931 to 2025, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00047339; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Redwood City's climate compare?
Redwood City is warmer than 82 of the other 218 places with their own NOAA record in California, and wetter than 128. Across the 7,247 U.S. stations with normals, its annual mean of 59.4°F is warmer than 73%.
In the Köppen classification computed from these normals, Redwood City is Csb: temperate, dry-summer, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Redwood City share this climate record?
8 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- San Mateo, CAalso near: Pacifica (9 mi, 57.4°F a year); Half Moon Bay (9 mi, 54.9°F a year)103,006 people · 7 mi NW
- Foster City, CA32,657 people · 6 mi N
- San Carlos, CA29,403 people · 2 mi NW
- Belmont, CA27,132 people · 4 mi NW
- North Fair Oaks, CA13,327 people · 2 mi E
- Atherton, CA7,022 people · 2 mi SE
- Emerald Lake Hills, CA4,396 people · 2 mi SW
- Baywood Park, CA1,481 people · 7 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Redwood City's climate
What is the coldest month in Redwood City?
December, with a normal high of 59°F and a normal low of 40°F. The warmest is July (81°F by day, 57°F at night).
Does it snow in Redwood City?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in Redwood City?
December, with 3.92 in of precipitation in a normal year; the driest is July with 0.00 in.
What plant hardiness zone is Redwood City in?
The USDA's 2023 map puts Redwood City in zone 10a across its 3 ZIP code areas (10a in 94063, the largest). By the same method at Redwood City's NOAA station, the coldest night of a typical year reaches 29°F (22 years, 1991-2020): zone 9b.
How late can frost come in Redwood City?
In half of years the last 32°F night comes after January 17; in one year in ten it comes after February 16. Waiting until February 16 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Redwood City in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Woodside, CA4 miles from this station, 60.1°F a year
- Palo Alto, CA6 miles from this station, 58.5°F a year
- Half Moon Bay, CA11 miles from this station, 54.9°F a year
- Sunnyvale, CA12 miles from this station, 59.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made